Don't beat yourself up--it's more helpful to be kind to yourself. Get back on track & concentrate on moving ahead. You've already done a great job and a slip does not mean you won't continue to well. At the worst, you may need a few days to get back into ketosis.

At some point, it's worth getting curious, in a friendly way, about what caused the off plan eating for you--stress? diet fatigue? triggers? etc.

A lot of 3FCers recommended a book that I found helpful when I had a similar experience as you: Brain Over Binge by Kathryn Hansen.